St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' based on blade width and stolon presence; however, definitive cultivar identification requires growth rate analysis.
Hardiness Zones
USDA Zones 8-11; poor cold tolerance, susceptible to winter kill in temperatures below 20°F (-7°C).
About This Grass
A coarse-textured, low-growing grass that forms a thick sod. It maintains a deep blue-green color in warm months and goes dormant (turning tan/brown) after the first hard frost. It features prominent, thick runners and compressed stems.
Blade Characteristics
Coarse blade width (8-10mm), flat shape with a distinctively rounded or 'boat-shaped' tip. Blades are folded in the bud (folded vernation). Ligule is a fringe of short hairs; auricles are absent. The collar area is continuous and narrow.
Root System
Fibrous, moderate to deep root system arising from nodes along the stolons. Slow to establish from seed (usually sodded or plugged); forms a thick thatch layer over time.
Growing Information
Origin Region
Coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; adapted to tropical and subtropical climates.
Growth Habit
Stoloniferous; spreads aggressively via thick, creeping above-ground stolons to form a dense, carpet-like mat.
Sunlight & Water Needs
Partial sun to full sun; one of the most shade-tolerant warm-season grasses (needs 4-6 hours). High water requirement; poor drought tolerance compared to Bermuda, as it wilts and rolls its leaves quickly when dry.
Mowing & Maintenance
High maintenance; mowing height of 2.5 to 4.0 inches. Requires frequent mowing to prevent thatch buildup. Needs 2-4 lbs of Nitrogen per 1000 sq ft annually. Vulnerable to 'Gray Leaf Spot' (visible in image as circular tan lesions).
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal lawns); moderate traffic tolerance but slow to recover from heavy wear; highly susceptible to Chinch Bugs and Sod Webworms.
Ecological Information
Introduced/Naturalized in North America; provides soil stabilization in sandy coastal soils. Low wildlife value in manicured lawns; can be invasive in native riparian habitats if escaped.